On the basis of distribution channel, the sildenafil market is segmented into hospital pharmacy, retail pharmacy, online pharmacy and others. Sildenafil works by relaxing the blood vessels of lungs, which allows easy blood flow. You’ll soon start receiving the latest Mayo Clinic health information you requested in your inbox. You can take sildenafil with or without food. If you have certain health conditions or are taking certain medications, your doctor may tell you to take sildenafil less often. If you experience chest pain, dizziness, or nausea during sexual activity, call your doctor immediately and avoid sexual activity until your doctor tells you otherwise.Sildenafil is available through Hims by prescription in , , mg pills starting at $4. Drugs & Medications Sildenafil Tablet Sildenafil Tablet – Uses, Side Effects, and More Common Brand (S): Viagra Generic Name (S): sildenafil Uses Sildenafil is used to treat male. This drug is more popular than comparable drugs. It is available in generic and brand versions. Generic sildenafil is covered by most Medicare and insurance plans, but some pharmacy coupons or cash prices may be lower. Compare PDE5 inhibitors.